Noiseblocker NB-BlackSilentPRO PK-1/2/3

The German Noiseblocker Company doesn’t need a special introduction, because their fans were among the leaders of our previous test session having totally impressed us with their unprecedentedly low noise. Today we are going to test NB-BlackSilentPRO PK-1, PK-2 and PK-3. I wonder if they will be able to retain the leadership crown won by their 120 mm brothers last time.

The shape and style of the fan package design didn’t really change, they have only become a little bigger, which is quite logical:

The fans are bundled with a shock-absorbing frame made of soft rubber, two cables of different length and long retention screws with nuts:

It is the first time that we come across a fan with an anti-vibration frame like that. What an interesting alternative to the common silicone mounts…

The impeller diameter is 130 mm. The blades are shaped in such a way that they feature wide front part and sharp front edge. The inside of the fan frame has two slightly raised ribs:

There are no holes in the fan frame, only bushes (why do they need them at all, I wonder?). The three models differ by their rotation speed and all other characteristics depending on it. PK-1 fan rotates at 700 RPM, creates 35.3 CFM airflow, generates 9 dBA of noise and boasts 0.952 mmH2O static pressure. PK-2 and PK-3 fans has the following corresponding specs: 1200/1700 RM, 54.7/90.1CFM, 20/27 dBA and 1.295/1.781 mmH2O.

The rotors of all three fans are 45 mm in diameter and covered with stickers reading their voltage, model name and rotation speed:

NB-BlackSilentPRO PK-1/2/3 are built with noiseless and very long-lasting NB-NanoSLI bearings with 120,000-180,000 hours MTBF. Besides their record-breaking life span, the motors of these fans can start at a very low voltage (only 4.5 V according to the official specifications and 3.5-4.2 V according to our own measurements) and consume only 0.72 W, 1.08 W and 2.4 W of power for PK-1, PK-2 and PK-3 models respectively. Moreover, NB-BlackSilentPRO PK-1/2/3 boast some sort of cable-management, with only a three-pin connector on a short cable coming out of the actual fan and two cables, 200 and 500 mm long, included among the bundled accessories. You can use either of these cables or connect them with one another for a total of 700 mm length.

This German fan maker decided not to fall behind their Austrian competitor and also provides each of their fans with a 6-year warranty. NB-BlackSilentPRO PK-1/2/3 fans are priced at about $20 per fan.

Let’s find out how effective these Noiseblocker fans actually are:

NB-BlackSilentPRO PK-1/2/3 confirmed the previous success of their 120 mm brothers to the utmost extent. The junior fan in this lineup, NB-BlackSilentPRO PK-1, is extremely quiet, although this quiet operation comes at a price: not very high airflow readings. The medium model, NB-BlackSilentPRO PK-2, must be the most popular one in terms airflow-to-noise ratio. By the way, it is only a little bit quieter than the top model - NB-BlackSilentPRO PK-3, but overall, they show very close results at identical rotation speeds. These fans remain acoustically comfortable up to 940-960 RPM and are very quiet at 770-790 RPM speed. In terms of airflow volume, Noiseblocker NB-BlackSilentPRO PK-2 and -3 models are in the good center of the rating list getting very close to the top three.